Morris Louis Bernstein (November 28, 1912 – September 7, 1962), known professionally as Morris Louis, was an American painter. During the 1950s he became one of the earliest exponents of Color Field painting. While living in Washington, D.C., Louis, along with Kenneth Noland and other Washington painters, formed an art movement that is known today as the Washington Color School.

All of the Color Field artists were concerned with the classic problems of pictorial space and the flatness of the picture plane. In 1953, Louis and Noland visited Helen Frankenthaler's New York studio, where they saw and were greatly impressed by her stain paintings especially Mountains and Sea (1952). Upon their return to Washington, Louis and Noland together experimented with various techniques of paint application. Louis characteristically applied extremely diluted, thinned paint to an unprimed, unstretched canvas, allowing it to flow over the inclined surface in effects sometimes suggestive of translucent color veils. The importance of Frankenthaler's example in Louis's development of this technique has been noted.[2] Louis reported that he thought of Frankenthaler as the bridge between Jackson Pollock and the possible. However, even more so than Frankenthaler, Louis eliminated the brush gesture, although his flat, thin pigment is at times modulated in billowing and subtle tones.

In 1954, Louis produced his mature Veil Paintings, which were characterized by overlapping, superimposed layers of transparent color poured onto and stained into sized or unsized canvas.[3] The Veil Paintings consist of waves of brilliant, curving color-shapes submerged in translucent washes through which separate colors emerge principally at the edges. Although subdued, the resulting color is immensely rich. In another series, the artist used long parallel bands and stripes of pure color arranged side by side in rainbow effects. The painting Tet is a good example of his Veil Paintings.

The thinned acrylic paint was allowed to stain the canvas, making the pigment at one with the canvas as opposed to "on top". This conformed to Greenberg's conception of "Modernism" as it made the entire picture plane flat.[4]

Louis destroyed many of his paintings between 1955 and 1957. He resumed work on the Veils in 1958–59. These were followed by Florals and Columns (1960), Unfurleds (1960–61)—in which rivulets of more opaque, intense color flow from both sides of large white fields of raw canvas—and finally the Stripe paintings (1961–62). Between summer 1960 and January/February 1961, he created about 150 Unfurleds, generally on mural-size canvases.[5]

Morris Louis was diagnosed with lung cancer in 1962 and soon after died at his home in Washington, D.C. on September 7, 1962. The cause of his illness was attributed to prolonged exposure to paint vapours.[7] The Estate of Morris Louis is represented exclusively by Diane Upright, a former professor of fine art at Harvard University.[9]